#include "pid.h"
#include "stddef.h"

#define LimitMax(input, max)                                                                                           \
    {                                                                                                                  \
        if(input > max)                                                                                                \
        {                                                                                                              \
            input = max;                                                                                               \
        }                                                                                                              \
        else if(input < -max)                                                                                          \
        {                                                                                                              \
            input = -max;                                                                                              \
        }                                                                                                              \
    }

/**
 * @brief          pid struct data init
 * @param[out]     pid: PID struct data point
 * @param[in]      mode: PID_POSITION: normal pid
 *                 PID_DELTA: delta pid
 * @param[in]      PID: 0: kp, 1: ki, 2:kd
 * @param[in]      max_out: pid max out
 * @param[in]      max_iout: pid max iout
 * @retval         none
 */
/**
 * @brief          pid struct data init
 * @param[out]     pid: PID结构数据指针
 * @param[in]      mode: PID_POSITION:普通PID
 *                 PID_DELTA: 差分PID
 * @param[in]      PID: 0: kp, 1: ki, 2:kd
 * @param[in]      max_out: pid最大输出
 * @param[in]      max_iout: pid最大积分输出
 * @retval         none
 */
void PID_Init(PidTypeDef* pid, uint8_t mode, const float PID[3], float max_out, float max_iout)
{
    if(pid == NULL || PID == NULL)
    {
        return;
    }
    pid->mode = mode;
    pid->Kp = PID[0];
    pid->Ki = PID[1];
    pid->Kd = PID[2];
    pid->max_out = max_out;
    pid->max_iout = max_iout;
    pid->Dbuf[0] = pid->Dbuf[1] = pid->Dbuf[2] = 0.0f;
    pid->error[0] = pid->error[1] = pid->error[2] = pid->Pout = pid->Iout = pid->Dout = pid->out = 0.0f;
}

/**
 * @brief          pid calculate
 * @param[out]     pid: PID struct data point
 * @param[in]      ref: feedback data
 * @param[in]      set: set point
 * @retval         pid out
 */
/**
 * @brief          pid计算
 * @param[out]     pid: PID结构数据指针
 * @param[in]      ref: 反馈数据
 * @param[in]      set: 设定值
 * @retval         pid输出
 */
float PID_Calc(PidTypeDef* pid, float ref, float set)
{
    if(pid == NULL)
    {
        return 0.0f;
    }

    pid->error[2] = pid->error[1];
    pid->error[1] = pid->error[0];
    pid->set = set;
    pid->fdb = ref;
    pid->error[0] = set - ref;
    if(pid->mode == PID_POSITION)
    {
        pid->Pout = pid->Kp * pid->error[0];
        pid->Iout += pid->Ki * pid->error[0];
        pid->Dbuf[2] = pid->Dbuf[1];
        pid->Dbuf[1] = pid->Dbuf[0];
        pid->Dbuf[0] = (pid->error[0] - pid->error[1]);
        pid->Dout = pid->Kd * pid->Dbuf[0];
        LimitMax(pid->Iout, pid->max_iout);
        pid->out = pid->Pout + pid->Iout + pid->Dout;
        LimitMax(pid->out, pid->max_out);
    }
    else if(pid->mode == PID_DELTA)
    {
        pid->Pout = pid->Kp * (pid->error[0] - pid->error[1]);
        pid->Iout = pid->Ki * pid->error[0];
        pid->Dbuf[2] = pid->Dbuf[1];
        pid->Dbuf[1] = pid->Dbuf[0];
        pid->Dbuf[0] = (pid->error[0] - 2.0f * pid->error[1] + pid->error[2]);
        pid->Dout = pid->Kd * pid->Dbuf[0];
        pid->out += pid->Pout + pid->Iout + pid->Dout;
        LimitMax(pid->out, pid->max_out);
    }
    return pid->out;
}

/**
 * @brief          pid out clear
 * @param[out]     pid: PID struct data point
 * @retval         none
 */
/**
 * @brief          pid 输出清除
 * @param[out]     pid: PID结构数据指针
 * @retval         none
 */
void PID_clear(PidTypeDef* pid)
{
    if(pid == NULL)
    {
        return;
    }

    pid->error[0] = pid->error[1] = pid->error[2] = 0.0f;
    pid->Dbuf[0] = pid->Dbuf[1] = pid->Dbuf[2] = 0.0f;
    pid->out = pid->Pout = pid->Iout = pid->Dout = 0.0f;
    pid->fdb = pid->set = 0.0f;
}
